If the tool is configured for reading, it's not necessary to specify the file
size, as the tool will stat each file to determine its size.

In addition, when the random workload is used, the tool will run forever. With
the sequential workload, the tool will iterate through each file in numerical
order, and exit once it has read/written each file.

Future Work

This tool is a work in progress, and there is some duplicated code which can be
refactored. In addition, more tunables are needed to tune the file size, I/O
size, workload type, and files/directories used in this test.